Oedogonium trioicum Woronichin 1923, p. 99; 1923a, p. 141 



PL 37, Fig. 10 



Macrandrous; dioecious. Vegetative cells variable in proportions; 

 elongate, or short-cylindric; 3.5-5/x in diameter, 10-22/i, long. Oogonia 

 solitary ( rarely 3 in series ) ; ellipsoid or oblong-ellipsoid; operculate; 

 division superior; 25-27/a in diameter, (13)-17-(26)/i, long. Oospores 

 ellipsoid to subovate; wall smooth; (14)-17-20-(21)/i long. Anther- 

 idia 4/i, in diameter, Sfi long. 



Our specimens are assigned here on the basis of the shape and 

 size of the oogonium. The oospores in our specimens are only slightly 

 ellipsoid, and the faint violet color described for Oe. trioicum was 

 not observed in the preserved material. 



In a roadside fosse. Wis. 



Oedogonium Welwitschii West & West 1897, p. 5 

 PI. 38, Figs. 7, 8 

 Macrandrous; dioecious. Vegetative cells cylindric, (18.5)-20-28ju, 

 in diameter, (25)-37-84/x long. Oogonia 1-3; subglobose or 

 subovate-globose; operculate; division superior; 43-50ju, in diameter, 

 43-52/A long. Oospores globose; wall thick, smooth; (35)-40-42-(43)/a 

 in diameter. Cells of male filament 17-20/* in diameter, 35-80/x long. 

 Antheridia 16-18/i. in diameter, 7-9/a long. 



Attached to grass and other submerged aquatics. Wis. 



Section 4 

 Macrandrous — Monoecious — Operculate 



Oedogonium Ahlstrandii Wittrock in Wittrock & Nordstedt 1882, 



Algae Exsic. No. 401 



Macrandrous; monoecious. Vegetative cells cylindric, 10-18/* in 

 diameter, 30-180/t long. Oogonia solitary; ellipsoid; operculate, 

 opening superior; 35-42/* in diameter, 57-69/^. lo^^g- Oospores ellip- 

 soid; filling the oogonia; wall smooth; 34-41/* in diameter, 53-62/* 

 long. Antheridia 13-17/* in diameter, 9-12/* long. 



Mich. 



Oedogonium autumnale Wittrock 1875, p. 11 

 PI. 34, Figs. 11, 12 



Macrandrous; monoecious. Vegetative cells cylindric, ( 16) -18.5- 

 20/* in diameter, (25) -74-80/* long. Oogonia solitary; globose or 

 obovoid-globose; operculate; division superior; 39-45/t in diameter, 

 39-45.7/1 long. Oospores globose; not filling the oogonia; wall thick, 

 smooth; 37.5-39- (42)/* in diameter, 37.5-39- (42)/* long. Antheridia 

 1-2, 15.5/* in diameter, 7.4/* long. 



On submerged vegetation. Wis. 



[189] 



